He said the car was "a safe, affordable and all weather transport - a people's car, designed to meet all safety standards and emissions laws and accessible to all".

Environmental critics have said that the car will lead to mounting air and pollution problems on India's already clogged roads.

But Tata said the car had passed emission standards and would average about 50 miles to the gallon, or five litres per hundred kilometres.

The firm also said it would introduce a diesel version of the Nano at a later date.

'Family transport'

At the unveiling ceremony Mr Tata said: "I observed families riding on two-wheelers - the father driving the scooter, his young kid standing in front of him, his wife seated behind him holding a little baby.

TATA'S NANO

3.1m long, 1.5m wide, 1.6m high

Can seat four to five people

Meets European emission standards

Costs 100,000 rupees ($2,500)

Tata hopes to eventually export the car

Source: AFP

"It led me to wonder whether one could conceive of a safe, affordable, all-weather form of transport for such a family.

"Tata Motors' engineers and designers gave their all for about four years to realise this goal.

"Today, we indeed have a People's Car, which is affordable and yet built to meet safety requirements and emission norms, to be fuel efficient and low on emissions."

Ravi Vangala, of Hyderbad, India, said: "I... congratulate Tata for his dream, and I will definitely buy the Tata Nano car."